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Bentley Type R Turbo 6.3 V8 1989 - Cold start problem with misfire #

Posted by Vince Mosley on October 19, 2011, 4:05 pm

Year of Manufacture *: 1989
Engine Size and Code *: 6.3 v8
( Optional ) ECU Type: bosch ke jetronic

Ok i have been looking at this car over the summer . Originally had a cold start problem with misfire on startup. Diagnosed water contamination in the past so fitted new injectors and KMI rebuilt metering head, flushed and cleaned system and tank, problem solved. It then developed a hesitation under acceleration so new leads, caps,rotor arms (twin dissy), plugs . It now starts from cold , and if switched off when hot will start up immediately no problem but if its left for a couple of hours when hot it starts up rough, like the injectors have drained off. It never fails to start. I seem to remember the RS Turbo's with the same system having a problem with the diaphragm in the accumulator. Has any one had this with this system ? or car? or any ideas where to look next? Car is away in Durham at the moment but will be back in the next couple of weeks.
Thanks in advance

Re: Bentley Type R Turbo

Posted by martin simonsohn <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3223' width='330' height='300' border=0 style='border:none;'> on October 19, 2011, 4:48 pm, in reply to "Bentley Type R Turbo"

hi have had a little to do with rolls and Bentley but not with the turbo
found miss fire and rough running with the erg pipework blocking and fouled.
also how fresh is the fuel in the tank and have you checked the fuel pressure and engine temp sensor.
after thought can you smoke test the inlet
u could have an air leak on the inlet causing it to run lean on the start
what are the emission like at idle and light throttle

Re: Bentley Type R Turbo

Posted by David Davies <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5218' width='330' height='300' border=0 style='border:none;'> on October 19, 2011, 5:46 pm, in reply to "Bentley Type R Turbo"
David Davies

Hot starting problems can mean fuel pressure is not holding up when at rest.Suggest fit pressure gauge to evaluate rest pressure.If pressure drops clamp off pipe from fuel pump,if this stops pressure drop,suspect pump non return vslve.If pressure still drops suspect leaking injectors.There are of course many other possibilities for leakage.

Re: Bentley Type R Turbo

Posted by Vince Mosley <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2919' width='330' height='300' border=0 style='border:none;'> on October 20, 2011, 12:49 pm, in reply to "Re: Bentley Type R Turbo"
Vince Mosley

Thanks guy for the speedy replies. The injectors as i have said are brand new, the fuel is fresh, the CTS has been replaced for new. I would have thought that if it was a pressure drop in the line it would occur on initial start up in the morning, but its fine then. As i say its only when it has stood from hot for 2 hrs. Left over night its fine. The emissions are correct or were correct when i checked it last. Once its back in the workshop i will test a little further and report back.